a small bead of silicone or RTV sealant in the reflector groove will do the trick. Leave the "open" end of the cord to line up at one of the reflector slots so that it can be positioned such that any condensate on the reflector or lense is free to drain out. I lay the glass lens on top of the cord and add a small weight to the lens to let it all cure flat in a perfect plane. Install the reflector the next day...